eK9aT10pSi

iTrader: (1)

hey guys, what would be the ideal tire pressure for the optional 18" rims? i was thinking 32 would be too low. i just got new tires, so i thought i would use the ideal pressure from the beginning to prevent incorrect tire wear.

mapid145

i have my 17"s at 33 cus its the recommended pressure.. i think urs would be the same.. not sure though

I VIK I

iTrader: (1)

For my car the mech recommends 31 PSI

Dont go by what the sticker thing in the door pannel says, Its for when the car is completely full.

RipitRon

It is posted on the tire, And if you are looking for the most life from the tire Use it.

coolmax05

iTrader: (8)

Sorry my friend...the "max" tire pressure is posted on the tire. Tire manufactures post this number only-not the range (they have no idea what kind of car it's going on). The recommended tire pressure is obviously 32 PSI cold. For performance/quicker steering you'll want to be higher. For comfort you'll probably want to stay at 32 or even slightly lower. Depending on racing conditions they will probably end up being different front to rear to control over or understeer. Then there is longevity.
If you inflate them to high they will wear in the middle of the tire faster. If you underinflate them they will wear on the edges faster.

It really comes down to your own preferences and priorities (or the wife in some cases).

taste great, less filling...

!PrjctMax!

iTrader: (38)

32 for normal driving
28+ for a more comfortable ride
34+ for better gas mileage (obviously 50 will be a little too much)

RipitRon

I think you are missing the point, I might be wrong here I have been many times but the question was what is the right tire pressure for wear, and that is the factory recomendation, I have worked with many tire MFG, Goodyear, hoosier, pirelli And the factory recommendation is based on several things and the weight of the car has some to do with it, But if you buy the right tire for the weight rating and the set tire pressure the tire will live longer. Now if you want to drive it hard then a different story but for life the factory recomendation is the best bet!

coolmax05

iTrader: (8)

What point might I be missing Ron? Do tell...

You implied the tire has the recommended tire pressure printed right on it. It does not! I said and I quote..."the recommended tire pressure is 32 PSI@cold". That is factory!!!

What am I missing???

RipitRon

What your where missing was the question, which yes you touched on but it is 32 psi!

DeusExMaxima

iTrader: (1)

Ideal varies according to the tire itself. If your tire has max pressure of 35, I beleieve you can vary this by about 5 lbs either way depending on your application. For example if I were to autocross, Id bump them up to 40. If I were going on a long trip and wanted a softer ride, u could drop them down to 30.

lightonthehill

I can only repeat what coolmax5 is saying. In fact, I will go one further: PAY NO ATTENTION to the air pressure specified on the tire.

The ONLY purpose for that number is to tell you the ABSOLUTE MAXIMUM pressure the tire can handle, no matter how heavy the load in the car may be. The number normally found there on tires that fit the Maxima will be between 44 and 50 pounds. Inflating to that number, even if the car is carrying four people with luggage, will ride like heck, be brutal on your suspension, cause control problems on bumpy roads, and wear the tread out in the middle fairly quickly.

The recommended pressure for ANY vehicle is on the vehicle itself, not the tire. The pressure specified for the SE is 32, and for the SL is 33. Those are good pressures that give decent rides. But better control, better fuel mileage and, in my case, more even tire wear seem to 'happen' around 35 psi in front and 33 psi in the rear.

More aggressive drivers may prefer a pound or two more, but, in normal driving, anything over 37 psi will cause the middle of the tire to wear out noticably more quickly than the edges.

Likewise, 28 psi will give a great ride, but, unless you live in rural Texas and don't do much turning, 28 will wear out the edges of the tire fairly quickly.

I personally carefully measure the depth of the grooves across the tread of each tire every few months, moving the psi slightly up or down as needed in order to have the tire wear evenly. That maximizes the miles I get from my tires, and seems to give the best overall combo of ride and performance..

But then coolmax5 pretty much already said all this.

Patsky

The maximum tire pressure is what is used to compute the load index of the tire. For a given tire size the ability to hold more pressure = ability to carry a bigger load. For example, our stock goodyears have a load index of 96, so each tire can hold 1565 pounds and operate normally granted it is filled with the maximum pressure on the sidewall. It says nothing about performance, wear, or efficiency except that it should safely be able to handle the weight under normal driving conditions. Each tire is constructed differently, so the load ratings and required tire pressures for performance, wear, load carrying, etc. will have to be figured out on a case-by-case basis and will be different depending on what you want to do with the tire. Read: it's all up to you, but don't under-inflate (duh).
You can even do a ratio between the recommended pressure (given by nissan), the gross vehicle weight rating (gvwr), and the maximum tire pressure to approximate the necessary tire pressure at your vehicle's fully loaded weight (gvwr). This pressure is the MINIMUM to use if you load your car to the maximum weight that nissan says the car can do. Take our factory goodyears for example:

max press: 44psi
load rating: 1565 lbs
recommended tire pressure: 32psi
number of tires: 4

(32/44)*1565*4 = 4553lbs

That number, 4553, should be REALLY close to the vehicle's max gross weight, a.k.a. the gvwr. Mine says 4546 pounds for gvwr on the sill.


This method is what you should use to figure out safe (for maximum car loading) tire pressures to use if you go with different tire/wheel combinations. If, say, the new setup's load index is 87, or 1201lbs, at 41psi then you would work backwards to get:

gvwr tire pressure = (41*4546)/(4*1201) = 39psi

You can even use the sill plate's gross axle weight rating (gawr) to figure our the front/back pressure split for your fully burdened vehicle if you desire. Just use "2" instead of "4" in the equation above!

All that said, remember that it's still up to the operator to determine if more or less pressure is to be used in consideration of performance, wear, not fully loaded, etc.

Cheers,

Pat

DeusExMaxima

iTrader: (1)

Sorry, but I believe this is dangerous advice. The TIRE dictates pressure regulation, not the CAR. And, the maximum tire pressure indicated on the sidewall is NOT the absolute maximum pressure. As I indicated earlier, racers for decades, including me, have pumped up the tires beyond the maximum specified on the tire and then competed on them. Racers take tires to the limits, well beyond "normal" driving conditions.

I have never seen a maximum specified tire pressure between 44 and 50, not to say that it doesnt exist, because im sure it does. I believe my Dunlops are 41 lbs Maximum which is higher than most, and the average maximum I find on tires is 35.

Patsky

The Avon Tech M550A/S maximum inflation is 51psi with a load index of 96 (1565lbs) in 245/45/18. I run 32psi for reasons stated above and find it gives the correct wear pattern. According to the formula above, if I wanted to fully load my car I would have to run 37 psi, but that actually wears the center of my tires down too quickly.

coolmax05

iTrader: (8)

The average "Max" tire pressure for performance tires in 18X245-45 is about 50PSI@cold. This is a fact! I don't know if we are talking apples and oranges or cold versus hot but you "should not exceed" maximum cold tire pressure recommended by the tire manufacturer-Period! Racing or not.

What kind of tires are on your car Deus? For example, Dunlop Sport Maxx's have a max tire pressure of 50PSI@cold. If you exceeded that by 5PSI you'd be running at 55PSI@cold and as high as 67PSI@hot. That my friend would be hella dangerous. My tires are Bridestone PP's and the max is 50PSI. Same goes for Conti-Contacts, Goodyear F1's, Avons, KDW2's, Yokohama ES100's, Michelin PS2's, and many others. I suspect you are talking about the car manufactures recommendations. And yes you can run well over that. Especially for racing with no concern over longevity.

Personally, I run my fronts at 35PSI@cold and the rears at 33PSI@cold. This gives me "MY" prefered ride quality and performance tradeoffs. Longevity is not a priority for me. I'd assume to have more pleasure for shorter distances than less pleasure for longer distances.

A interesting side-note. For really low profile tires you'll find that lower tire pressures sometimes do not equal better ride quality because of the stiff sidewalls.

taste great, less filling...

eK9aT10pSi

iTrader: (1)

hey guys, thanks for the responses. i didnt want to start a max pressure debate. i just wanted to know what would be good pressures to set the tire for daily driving. cars dropped with progress springs/struts/shocks. i figured i could raise it up but didnt know what would be a good psi to set it to. from reading, i am getting about 35 psi cold for the se 18" rims?

coolmax05

iTrader: (8)

Well, this will teach you to ask a simple question. With this site a thread is by default a debate. It should actually be called a "new debate" not new thread.
Just be happy we don't have the visuals up yet. Speaking of such...

DeusExMaxima

iTrader: (1)

Im running Dunlop Sport FM901 with max psi of 51. I raced at 45 psi and usually run 40 in the street. It seems most tires I have seen are around 35 psi. Racers have been running over max tire pressure for decades. It simply isnt true to state its dangerous to run above it.

coolmax05

iTrader: (8)

Dues c'mon man.

I respect your track times. you represent us well. You obviously know a lot more about racing than me. That I know. But I can read bro!

Dues, you said and I quote "I have never seen max tire pressure between 44-50". Then you said "I believe mine is 41". Then you said later "my Dunlops are 51".
Then you said "I race at 45PSI" which is below the max.

You also talked about how dangerous lightonthehill's advice was and I'm still trying to figure that one out. Then you say "the tire manufacturers max is NOT the absolute max??". You also said you race 5PSI over the max and it seems you don't (because you thought your max was 41???).

Almost every tire on SE's is exactly what lightonthehill said, 44-50PSI (or higher in your case). Please name ONE (1) 18' tire 245/45 that is max 35PSI.

Just one is all I ask seeing as though you see them all the time...

And you ripitron, how is this just touching on a subject? I said "The recommended tire pressure is obviously 32 PSI cold."
You said this which is the only reason I responded in the first place... "It is posted on the tire, And if you are looking for the most life from the tire Use it."

On second thought, make that a double bartender...

DeusExMaxima

iTrader: (1)

Right, I did say that. The tires I had for a long time BEFORE my present ones had pressure of 41. I just recently changed tires right before my Lone Pine race. I still say that MOST tires dont run pressures much above 40 and MOST of the ones I have seen in past were around 35. The higher performing tires run higher pressures, but most people dont run high performance tires. I would say more of us do here than the common maxima owner.

I have raced over the maximum pressure in the past MANY MANY time as have my fellow racers. The tires I have now, I didnt run over the maximum. The way tire pressure works is that FWD cars require higher pressure than rear tires to improve handling. If you "roll over" your tread, your running too low of a pressure. I have seen people run pressure in the high 40's+ when recommended pressure is 35. Lights advice is dangerous because if the car says to run 32 pounds max and the tire says max is 51, then 32 would most likely be way too low.

I'll take that double too bartender . . . . . .

DeusExMaxima

iTrader: (1)

Goodyear Eagles are 44, so are Dunlop Sport 8000, as are the lovely RS-A tires, and some others. And I know the Sumi's I ran was low 40's. But I could not find one in the 30's. I checked on tirerack.com.

I still say its foolish to follow the sticker on the car for tire pressure as opposed to the tire used.

Also, remember, my suspension is quite modified and i run wider rims and tiresa than OEM, so I can run lower pressures. If my tires rolled over at 51 psi, Im gonna `crank em up til they dont roll over. Its not dangerous to overfill em in the manner of which I have spoken. It is dangerous to under fill them. I have seen the results of that.

coolmax05

iTrader: (8)

It's all good my man. It's all in fun and I congradulate you on the great track times. If we were in the same town I'd buy you that double after you kiked by butt on the track.

I'm getting the Konis this week. I have been listening to you, and you are the reason I'm getting the konis along with "Prescence".

Remember, he who has the most fun wins!

DeusExMaxima

iTrader: (1)

U will love the Konis, cool. Id have that double with ya too!!! Let me know how u like em.

madmik

iTrader: (1)

For 18", service manual says 32 lbs COLD. The decal on your car's doorpost has the correct loading and pressure information if you are using the OEM tire size.

Some tire manufacturers recommend using the car manufacturer's label as a minimum tire pressure. Under-inflating a tire can increase its operating temperature, which may go beyond the temperature it was tested/designed for. Under prolonged use, the added stress can cause premature wear and also thread separation and possibly a blowout.

We could chat for hours on this subject but since you indicated you want to avoid uneven tire wear, try 32 lbs COLD as a minimum, and drive with a laid back attitude: slow cornering and braking, mild accelerations, observe the speed limit, rotate them and buy tires with a high Uniform Tire Quality Grade Standards (UTQG) number.

DeusExMaxima

iTrader: (1)

If you put ur tires on 32 cold, U better have good health and collision insurance! Do NOT follow that sticker, please.

eK9aT10pSi

iTrader: (1)

madmik, i just got new yokohama yk520's. it was set at 32 psi. i was just wondering about increasing the psi up to 35psi [at the highest].

vQ35LIFE

iTrader: (1)

**** , i still didn't get the point tho ? what is a good tire pressure a) for the front B0 for the back c) highway runs and d) dragstrip ???

eK9aT10pSi

iTrader: (1)

the only reason ive dropped tire pressure low is when going to the track.

lightonthehill

Deus - Not only is the advice I gave not dangerous, it is advice I have learned from 58 years of driving and from reading everything I can about tires for most of that time.

I know of no tire that would be considered for normal replacement use on the Maxima that would have a MAXIMUM PRESSURE (the ONLY psi shown on the sidewall of passenger tires) outside the range of 44 psi to 52 psi. Certainly not in the 30s that you mentioned. My Yoko 520s have ONLY a 51 psi on their sidewall. That would be an insane and very dangerous pressure to carry in any passemger car for normal driving with normal load.

In fact, inflating tires to the psi shown on the sidewall of a tire under any condition except a very unusually heavily loaded car should be considered dangerous. The tires would have almost no give, and would ride very rough. This would be hard on your suspension, and would definitely result in premature wearing of the middle of the tread.

The advice I gave in my earlier post was to not use the tire sidewall maximum psi as a guide to inflating your tires, but go with the psi Nissan specifies for the Maxima, or fairly near thar that. This is advice frequently seen in print, and I am surprised you have not seen it many times. I also said drivers could move up or down from that as their particular driving situation warrants. That is not only NOT dangerous advice; that is the sensible approach to properly inflating a passenger car tire. And has been for decades.

madmik

iTrader: (1)

According to the NHTSA, you need to rely on NISSAN's recommended pressure. In the owner's manual (do-it-yourself section), NISSAN says minimum 32 psi and maximum of 38 psi for the 245/45R18. So 35 psi is fine. Your Yokohama's are constructed to withstand up to 50 psi of pressure with up to 1764 lbs of weight on them.

According to Yokohama “In all cases, the determined inflation pressures based on actual load conditions should be considered minimum pressures. Operational air pressure can be set higher, but in no circumstances should they be set lower.”

Just note that as you increase the pressure, you slowly increase center tire wear rate. Good tire choice by the way. UTQG of 520. 60K miles according to Yoko.

coolmax05

iTrader: (8)

Nice write-up Madmik.

A lot of you remember the big Ford fiasco with rollovers. Ever since then tire pressure has become much more of a sensitive issue. Just remember that Ford & Firestone were playing with fire by trying to attain the best gas mileage figures and weight reduction by using "minimalist" techniques. What, Ford utilizing minimalism???

And I quote..."Smaller tires help lower the center of gravity, therefore lowering the rollover propensity. Lower tire pressures also help in this problem area too. Lower tire pressures however, with less air, create extreme temperatures and help promote or accelerate the rate of tire tread failures and separations. Some tires including the Wilderness AT were designed to be lighter in weight than comparable other tires to also fix the SUV's problem with excessive vehicle weight. Lighter tires, means lighter vehicle, creating better gas mileage. The lighter tires, with less rubber, with lower tire pressure on SUV's that are too heavy for the tire, with minimum numbers of belts are nothing more that pressure cookers waiting to explode."

We are not in the same minimalist category. We have room to spare but Lawyers & loose lawsuits (lawsuits=lawyers in suits) have gotten everybody rewriting car manuals to cover thier rears.

eK9aT10pSi

iTrader: (1)

thx madmik. i read that increasing tire pressure [not too much though] would help the car in being more efficient. and if the increase isnt too much, the wear should be pretty even.

xoomer.com

iTrader: (19)

I keep my 2004 SE wrapped in BF Goodrich at 35 PSI all around. Its all good.

madmik

iTrader: (1)

Another way to pick the best pressure is to do a few burnouts starting with 38 psi all the way down to 32 psi. The best even patch would be your guide. But its hard to do with BFGoodrich's KDW's.